At an annual tech conference in Austin, Texas that attracts over 40,000 early adopters, startups are desperate to make their mark.

South by Southwest is the place where companies like Twitter, Foursquare, and Skype-owned GroupMe have picked up their first users.

This year, one of the many startups that's invaded Texas is Lyft, a Silicon Valley startup that offers rides to people in cars that have ginormous pink mustaches pasted to the front.

Lyft has raised more than $7 million from investors such as Mayfield, K9 Ventures and Forerunner Ventures, and it operates in two cities, San Francisco and Los Angeles. It's a ride-sharing service and its founders say they're giving thousands of people a "lyft" per week. Tens of thousands of people use the app, which launched last June.

Lyft competes with other ride-sharing platforms such as Getaround and Uber. But unlike either of those, users aren't required to pay drivers. They just give a suggested donation amount. And while Lyft sounds a lot like hitchhiking, the founders say they've found a way to run their company legally.

Below, the founders explain what their startup is, and how they're promoting their company at South by Southwest. Their goal was to "keep Austin weird," so instead of picking conference goers up in cars, they've hired people to give people rides on piggyback.

Here's their demonstration, below.

*An earlier version of this post said the company had raised $1 million. It has raised over $7 million.